Can routine assessment of older people’s mental health lead to improved outcomes: A regression discontinuity analysis

Objective: To assess whether case finding for depression among people aged 65 and above improves mental health. Design: Opportunistic evaluation using a regression discontinuity analysis with data from a randomised controlled trial. Setting: The REFORM trial, a falls prevention study that recruited patients from NHS podiatry clinics. Participants: 1010 community-dwelling adults over the age of 65 with at least one risk factor for falling (recent previous fall or fear of falling). Intervention: Letter sent to patient’s General Practitioner if they scored 10 points or above on the 15-item Geriatric Depression Scale (GDS-15) informing them of the patient’s risk of depression. Main outcome measure: GDS-15 score six months after initial completion of GDS-15. Results: 895 (88.6%) of the 1010 participants randomised into REFORM had a valid baseline and six-month GDS-15 score and were included in this study. The mean GDS-15 baseline score was 3.5 (SD 3.0, median 3.0, range 0–15); 639 (71.4%) scored 0–4, 204 (22.8%) scored 5–9 indicating mild depression, and 52 (5.8%) scored 10 or higher indicating severe depression. At six months follow-up, those scoring 10 points or higher at baseline had, on average, a reduction of 1.08 points on the GDS-15 scale (95% confidence interval -1.83 to -0.33, p = 0.005) compared to those scoring less than 10, using the simplest linear regression model. Conclusion: Case finding of depression in podiatry patients based on a GDS-15 score of 10 or more followed by a letter to their General Practitioner significantly reduced depression severity. Whether this applies to all older patients in primary care is unknown. Further research is required to confirm these findings. Regression discontinuity analyses could be prespecified and embedded within other existing research studies.